It is very generally supposed that it is the business and profession of science "to explain" things--that is to say, to show how this or that must and does come about in consequence of the operation of the great general properties of matter, known as the "laws" of chemistry and physics. This is true enough, but it is equally the work of science to assert that of many things for which mankind demands "an explanation," there is no explanation. It is further the work and the service of science to destroy and to remove from men's minds the baseless and pretended "explanations" which are no explanations but causes of error, blindness, and suffering. Science, the destroyer of "explanations," is the purifier of the human mind, its cleanser from the crippling infection of prehistoric error and from domination by the terrifying nightmares of our half-animal ancestry. Finally, in reference to the very ancient attempt to "explain" life and consciousness by the assertion that they are due to "spirits" which enter the bodies of animals and men, I must caution the reader against supposing that--for those who do not accept the belief that such spirits exist--the gravity and mystery of the manifestations of life and consciousness are in any way lessened. Those who reject the belief in "spirits" do not in consequence reject the ethical and moral doctrines which have too long been rendered "suspect" by the shadow cast over them by ancient superstition. The disappearance of that shadow will reveal friends where enemies were supposed to be entrenched. At the meeting of the British Association in 1879 I delivered an address on "Degeneration: a Chapter in Darwinism." In the printed version of that address, published in the same year, there are some statements bearing on the matter above discussed which I reproduce here, since I can still make them with conviction. "Assuredly it cannot lower our conception of man's dignity if we have to regard him as 'the flower of all the ages' bursting from the great stream of life which has flowed on through countless epochs with one increasing purpose, rather than as an isolated miraculous being, put together abnormally from elemental clay, and cut off by such portentous origin from his fellow animals and from that gracious nature to whom he yearns with filial instinct, knowing her, in spite of fables, to be his dear mother." "A certain number of thoughtful persons admit the development of man's body by natural processes from ape-like ancestry, but believe in the non-natural intervention of a Creator at a certain definite stage in that development, in order to introduce into the animal which was at that moment a man-like ape, something called 'a conscious soul' in virtue of which he became an ape-like man."